ArcHydro and HEC-GeoHMS: Calculating Basin/River Slopes

Discussion created by mhross88 on Nov 17, 2011
Latest reply on Jan 14, 2014 by
I have been using ArcHydro and HEC-GeoHMS to analyze a watershed, and everything has been running rather well until I started trying to calculate slopes. Both ArcHydro and HEC-GeoHMS give me the error "The dataset does not have spatial reference. Please specify a valid spatial reference!".

All of my layers are in GCS_WGS_1984 so I do not understand why it is saying this.